Mike Leigh’s 1977 black comedy offers a glimpse inside the kitsch, pretentious world of Beverly and Laurence as they play host to newly arrived neighbours Tony and Angela, just putting their first foot on the property ladder, and Susan, local divorcee and mother of the eponymous teenager Abigail, who has ‘asked her Mum to leave’ so she can host her own ‘social gathering’, which is playing out in the background